Does unexplained weight loss mean cancer? Oncologist clears doubt and shares other symptoms to watch for

Are you losing weight, despite eating normally? Know when to visit a doctor because of unexplained weight loss.

Unexplained weight loss is generally flagged as a health concern, especially when you have not made any changes to your diet or exercise routine. Unexplained weight loss also frequently appears on lists of possible cancer symptoms. So, why does cancer cause weight loss, and when should it be treated as a warning sign?

We asked Dr Anindya Mukherjee, senior consultant in medical oncology at ShardaCare-Healthcity, why cancer causes weight loss and when unexplained weight loss means you need to visit a doctor.

Is weight loss only a sign of cancer?

There is no need to assume the worst right away. The oncologist added that while noticeable and persistent weight loss should not be ignored, it can also be a sign of several other health conditions.

He added, “Several conditions, including thyroid disorders, diabetes, digestive problems, infections and prolonged stress, can contribute to unexplained weight loss.”

Why is weight loss a cancer-related sign?

Cancer-related weight loss is not simply the result of eating less. Dr Mukherjee revealed that it can also occur because of complex changes in the body.

He noted, "The disease can trigger complex changes in the way the body uses energy. Cancer and the body's immune response can cause inflammation, which may alter metabolism and increase the breakdown of fat and muscle. As a result, a person may continue losing weight even when they are trying to eat adequately.”

Cancer can also make it difficult to eat enough. Dr Mukherjee described that the disease may affect appetite, taste, and digestion. Some people experience nausea, difficulty swallowing, or changes in taste, which can reduce food intake and lead to weight loss.

In certain cancers, the body's ability to absorb nutrients may also be affected. The oncologist named a condition, known as cancer cachexia, in which there is a progressive loss of weight, muscle, and strength. It is commonly seen in advanced cancer and cannot always be reversed simply by increasing food intake. ”

What are the other signs that accompany weight-loss related cancer?

Recurrent fever is one of the causes. (Picture credit: Pexel)

Dr Mukherjee shared the following signs to watch for:

• Persistent fatigue
• Loss of appetite
• Unexplained pain
• A persistent cough
• Changes in bowel habits, such as ongoing constipation or diarrhoea
• Difficulty swallowing
• Recurrent fever
• Night sweats
• Appearance of a new lump

These symptoms do not confirm cancer and can occur with several other conditions. However, the doctors advised seeking medical evaluation if they persist or accompany unexplained weight loss.

The oncologist also talked about the rate and extent: “Rapid or significant weight loss without a deliberate change in diet or physical activity should be evaluated, particularly if it continues over several weeks or is accompanied by other symptoms. Even gradual weight loss deserves attention if it has no clear explanation and continues despite normal eating habits.”

Doctors may consider a person's age, medical history, medications, lifestyle, appetite and other symptoms while determining the possible cause. Depending on the findings, blood tests, imaging or other investigations may be recommended.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.